Abstract [Co(phen)(NDA) 0.5 (H 2 O) 3 ] · H 2 O · 0.5NDA ( a ) (NDA = 2, 6‐naphthalenedicarboxylate ions, phen = 1, 10‐phenanthroline), and four novel coordination polymers (CPs), [ M (phen)(NDA)] n [ M = Co ( 1 ), Ni ( 2 ), Mn ( 3 ), and Cd ( 4 )], were synthesized under hydrothermal conditions. They were structurally characterized by single‐crystal X‐ray diffraction. Compound a was obtained by hydrothermal condition of 80 °C, displaying a zero dimension structure, and three coordinated water molecules located on the central Co 2+ ion. By decreasing the number of coordinated water molecules in a under high reaction temperature of 170 °C, the discrete motif of a was transferred into a 2D structure of 1 . Employing the same synthesizing condition like that of 1 , compounds 2 – 4 were prepared, of which 2 exhibited a 2D layer and compounds 3 and 4 feature novel 3D architectures. The magnetic susceptibilities of 1 – 3 were measured and discussed. There exist ferromagnetic coupling between the nearest metal ions in 1 and 2 , and the best theoretical fitting parameters were J = 3.96 cm –1 , g = 2.42 for 1 and J = 3.44 cm –1 , g = 2.02 for 2 . The study of the magnetic property of 3 shows the occurrence of weak antiferromagnetic interaction between Mn 2+ with fitting parameters of J = –0.80 cm –1 and g = 2.03, appearing short‐range antiferromagnetic ordering around 9 K.